I fully agree with chscag's opinion of Avast, its not necessary, is definitely a resource hog, constantly looking for stuff that doesn't exist.
I"m puzzled why EasyFind cannot delete the remaining files. I use EasyFind for app removal because as the name implies it's easy, just drag an drop and it usually works perfectly. I'm also a fan of Find Any File 2 which is a little more complex to use but works in much the same way. I notice EasyFind in current macOS does not require System Access like FAF2 which requires Full Disk Access in Security and Privacy settings.
You might like to try it, it's available for free download from here;
http://apps.tempel.org/FindAnyFile/index.php
It works in much the same way as the Finder, you type in a word or file type in the search box and it finds all instances. From the results window you can Delete Immediately or Move To Trash. If you move to trash you get the option to put the file back if you make an error. FAF2 is also able to display "invisible" files hidden in the system.
*As always care should be taken and it's advisable to perform a backup before mucking around with files at a system level.